SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa901bb4315636d1f6f520b259663de896049bf8c6187a07e9ef4efd12c5e21f' 
  AND token = '6VAAb7mqv+YicoAC1gNP7qP/M7cEuGRw4Lj9tmZtXFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}